alt_market_trends

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the behavioral disclosure burden. It states the data is credential-free public data from Alt's GraphQL API, which is valuable for auth expectations. It also explains the data source (sold/valuation data). It could disclose error/edge-case behavior more, but is strong for a read-only fetch.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences front-load the primary purpose and then add useful output/source context. Slightly repetitive ('Alt's own' appears three times), but every sentence earns its place and there is no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description tells the agent what output to expect (weekly/monthly/90-day change and current index value per category), notes the credential-free nature, and explains the source. With a single optional parameter and no output schema, this is complete enough for an agent to invoke correctly. It could mention how to discover valid categories, but the schema already points to alt_categories.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% for the single optional category parameter, including the exact-match and live-response caveats. The tool description adds only category-level context, which is nice but not necessary since the schema already documents the parameter thoroughly. Baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Uses a specific verb ('Get') and a specific resource ('Alt's card-market price-trend index'), and further distinguishes it by clarifying it is the same data as alt.xyz's Market Trends page. Among siblings like alt_top_movers, alt_categories, and alt_card_search, this is clearly unique.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides clear context: it is a credential-free, category-level index from Alt's sold/valuation data, which signals when this tool is appropriate. It does not explicitly name alternatives or state when not to use it, but the context is sufficient for an agent to select it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.